Air cooled spindle mounting for machine tools and the like



y 1943. G. D. scoTT 2,323,850

AIR GOOLED SPINDLE MOUNTING FOR MACHINE TOOLS AND THE LIKE Filed Oct. 7,1940 Gheraki D. Scofi Patented July 6, 1943 AIR COOLED SPINDLE MOUNTINGFOR MACHINE TOOLS AND THE LIKE Gherald D. Scott, Worcester, Mass.,assignor to The Heald Machine Company, Worcester, Mass., a corporationof Massachusetts Application October 7, 1940, Serial No. 359,992

1 Claim.

The present invention relates to the mounting, for example, of atool-carrying or work-carrying spindle, such as used in various types ofmachine tools, where, in the interests of precision operation, anyexpansion such as results from heat generated by the high-speed runningof the spindle, must be held to a minimum.

It is recognized in all precision tooling operations that such expansionnot only may have an adverse effect on the clearances for the spindlebearings, but also that the heating up of the support or housing forsaid bearings may cause the spindle axis to shift upwardly by an amountwhich, however slight, can nevertheless upset the accuracy of thetooling operation on a piece of Work in the machine.

An object of the present invention is to overcome these difficulties ina simple and inexpensive manner by utilizing the spindle rotation itselfas a means for rapidly dissipating the heat which is generated in thespindle mounting. Other and further objects and advantages of theinvention will more fully appear from the following detailed descriptionthereof, taken in connection with the accompanying drawing, in whichFig. l is a side elevational view, partly in section and with partsbroken away, of a spindle mounting embodying my invention.

Fig. 2 is an end view of the same, as seen from the line 2, 2 of Fig. 1.

Fig. 3 is a detached view, in side elevation, of an annular memberassociated with the other end of the assembly shown in Fig, 1.

Like reference characters refer to like parts in the different figures.

The drawing shows my invention, by way of example, as applied to thetool head or to the work head of a boring machine. Said head as showncomprises a hollow body or housing I which is adapted to be mounted inthe usual way, either on the base or on the reciprocatory table of themachine. Within the bore of housing I are provided suitable spaced-apartbearings, one of same being here shown as an anti-friction bearing 2 forthe journalling of a high-speed spindle 3, the latter having both endsprojecting beyond the housing I; on one of said ends is secured adriving pulley 4 of special construction as hereinafter described, whilethe other carries a plate 5, to which is attached, in any suitable way,a boring tool, not shown, or a workholder, not shown, as the case maybe.

According to my invention the body or housing I, on its external sideand top surfaces, as best shown in Fig. 2, is formed with a plurality oflongitudinally extending heat-radiating stationary fins or ribs 6, 6. Asuitable cover or shield I is preferably applied to the body I toenclose the space 8, along the sides and the top of said body, which isoccupied by said ribs or fins 6, 6.

Said space 8 containing the numerous relatively-thin fins 6, 6 of thebody I, serves as a manifold or duct for the continuous passage alongthe body I of a current of cooling air, which is supplied, according tomy invention, in sufficient quantity to dissipate and carry offpractically all of the heat which is generated by the highspeed rotationof the spindle 3 within the body or housing I. For the generation ofthis air current, during all periods of operation of the spindle 3, thelatters driving pulley 4 is made to serve as an air impeller or blower;tothis end, said pulley 4, inwardly of its belt-receiving surface,provides a peripheral flange or extension 9 which is formed on its innerface with a series of impeller blades Ill, I0. Suitably secured byinterior lugs II, to the adjacent end of the body I is a substantiallyannular member I2 forming a continuation of cover I and having anoutwardly projecting flange I3 within which the periphery of the pulleyflange 9 has a running fit,-the flanges 9 and I3 cooperating with theend of body I to enclose an annular space I4 wherein the blades ID areoperative. The ingress of atmospheric air to said space I4 is by way ofa plurality of suitable ducts or passages I5, I5 provided by the hub ofthe pulley 4,it being understood that the suction created by rotation ofthe blades ID in said space I4 will draw in air through said ducts orpassages I5, I5; all such air, under the impeller action of the bladesIO, N is forced through the spaces between lugs II, II (see Fig. 3) intothe manifold or passage 8 substantially surrounding the body I andcontaining the latters numerous fins or ribs 6, 6, said air escapingfrom said manifold only after passage along the full length of saidbody, through suitable openings or outlets I6, I6 provided by asubstantially annular plate Il, secured by bolts or the like to the endof the body I, just beyond the ends of the latters fins or ribs 6, 6.

Thus the cooling current of air set and maintained in motion by therotation of the spindle itself, is enabled by the above describedconstruction to absorb and carry 01f practically all of the heat whichis generated by the high-speed rotation of said spindle whereby iseffectively avoided any expansion in the spindle mounting member at oneend of said duct and having a flange substantially coextensive with saidcover, said driving devices including a pulley on said spindle, saidpulley making a running fit with said flange, and having air openingstherethrough. and fan blades on said pulley within said running fit, fordrawing in air through said openings, said duct or manifold receivingsaid air and conducting it, in heat-exchanging relation to said fins,longitudinally of said housing for substantially the full lengththereof.

GHERALD D. SCOTT.

